Sewing machine



July l, 1930. i H, F. GRUMAN Y 1,769,058

` SEWING MACHINE Filed 00t- 29. 1925 5 Sheets-Sheet l wfg/.5%

July l, 1930. H. F. GRUMAN 1,769,058

SEWING MACHINE Filed Dot. 29, 1925 5 Sheets-Sheet 2 H. F. GRUMAN July l, 1930.

SEWING MACHINE Filed Oct. 29, 1925 5 Sheets-Sheet 4 July l, 1930. H, F, GRUMAN. 1,769,058

SEWING MACHINE Filed 0G12- 29, 1925 5 Sheets-,Sheet 5 l)- y E15- VIO- Passed' Juiy 1,1936

g uriny HORACE ie. enuMaN,` ors'r. Louis, Missouni, AssIuNon ToLEwIsINvIsIBIiE sfiifrcri` MACHINE` COMPANY,l or iifrrnnv, MAINE, A conronA'rioN' OFMAI'NE; s

SEWING MACHINE n Application' led VGctc'lcer 29, 1925. Serial No. 65,580. i

This invention relates to sewing machines and more particularly such machines as may4 be used inthe manufacture of special garments to sew special seams therefor.

In sewing certain kinds of material such for instance as knit goods, as in the manufacture of underwear, sweaters,k bathing suits and the like, it is often desirable to Vcover thel edge of the work after sewing a seam with an over-stitch seam coveringthe trimmed edge so as'toprevent unraveling and also toimprove the appearance of the-finished seam.

Oneof the objects of this invention is to provide a sewing machine on which such knit goods may be operatedupon and which vwill be capable of sewing in one operation both a plain seam for sewing two or more thicknesses of material together, and an. over-stitchseam adapted to-covervand protectthe edgedof "the work outside of the iirst seam.

Another object of this invention. is to provide sewing mechanism which will be capable 'of sewing different kinds of seams simultaney n l 5 is a vertical transmission shaftgS mounted in bearings 9 in the casting 2. The shaft f8 Further ob ects will appearifrom the following description taken in connection with the accompanying dra-wings,v in which I Figure 1 is a vertical longitudinal section as seen from the front illustrating a sewing machine embodying this invent-ion --Yf A Figure 2 is a horizontal section of thesame taken about on line 2.-2, Figure v1; Figure 3 is a section on line-3-3, Figure 1 Figure 4 is a section on line i-ll, Figure 1;

` Figure 5 is a rear view of the machine;

Figure 6 is a detail of the loopermechanism forming a part of the over-stitching mechanisni;

Figure` 7 is a detail of the driving mechanismv for Vthe two main loopers;

Figure 8 is a detail of the trimmer lmechanism;

Figures 9, 10, and 11 are diagrammatical Views illustrating the'formation of theoverstitch; 'i 'i Figure 12 is al diagrammaticalview of the work illustrating the relations betweenlthe different operations, and

Figure 13' is a cross section of the nished work. Referring to the accompanying drawings 1 designates the base usually constructed of A.cast iron or similar material. `The base 1 moving parts and which is provided with a head.4 y l" f Main driving connections Mounted in bearings A: in the main hous-` ing 2 is a main horizpontaldrive shaft 5. This sha-ft may have mountedgthereon a driving l pulley v6 or other suitable means of connection .to alsuitable source `of power not shown.

Connectedlby means of bevel gears 7 to shaft is inturn connected bya pair of bevel gears 10 to `an upper horizontal shaftll mounted ,in bearings 12 on the casting 2. vThese shafts fornithe main driving connections for the machine. Y. f

Mounted on isa counter-weighted crank 13y connected by a pin 14 to a-connecting rod15 which, in turn is connected to a block 16 fixed to a needle bar 17 guided'ifor vertical movement in suitable bearings V,16 inthe head 3. it will be Vseen that operation of the shaft 11 will, through these connections, impart a. vertically reciprocating movement to the needle bar 17.

Fccdz'ng mechanism i Mounted in bearings 19 in the casting 2 is a rock shaft 20.- i Adjustably mounted on the shaft 2O is a sleeve 21 provided with an upwardly extending arm 22 `having formed therein an arcuate slot 28. The sleeve 22 may be fixed lto'theshaft 2O in adjusted position nby means of 'a set screw 24;-` Adjustably mounted on the shaft 5 is an, eccentric l25 working in a collar 26 attached to a forwardthe lend of thevupper shaftvll 1y extending arm 27 pivoted at its ends to a 'block 28 slidably mounted in the slot 23 and adapted to be fixed in adjusted position therealong. These connections provide that the rotation of the shaft 5 will impart, through the agency of the eccentric 25, a rocking movement to the arm 22 which in turn will Vrock the shaft 20. The extent of such movement may be adjusted by adjusting'the block 28 valong the slot 23, and the timingofsuch movement may be adjusted by adjusting the eccentric 25 on the shaft 5.

The shaft 2O extends to the left in Figure 1 and has fixed theretoan upwardly extending arm V29. A U-shaped bridge is shown interposed in the length of ythe shaft 20in order to bridge a transversely extending shaft 3l whose purpose will be 'described later. The arm 29 "is pivoted at its upper end to a feeding dog 32 having a toothed portion 33 adapted to engage the work in the usual manner. Rocking the shaft20 will rock the arm 29 so as to impart a reciprocating movement to the feeding dog 32 as will presently Vbe more fully described.

Loosely mounted on the shaft'20 is a sleeve p34 having an upwardly extending arm 35 providedwith an arcuate slot similar to the slot 23. The shaft 5 lcarries a second eccentric 36 similar to the eccentric 25 andv working in a collar 37 on an arm 38 similar to the arm 27 and similarly pivoted to a block 39,

'adjustable alongvthe arm 35 in a manner similar tothe adjustment of the block 28 along the arm 22. The sleeve 34 also has mounted thereon an upwardly extending arm 40 pivoted at its upper end to a pin 41 carrying a'sleeve 42 mounted on the end of a feed control arm 43. These connectionsv provide that the operation of the shaft 5 acting through'the eccentric 36 and the arm 38 will rock the sleeve 34 which, through the agency of the arm 40 imparts a forward and rearward reciprocating movement to the arm V43. This reciprocating movement is part of the feeding movement.

' The rearward end of the arm 43 is formed to provide a fork 44 adapted to embrace and provide a follower for an eccentric 45 also mounted on the shaft 5. The rearward end of the arm 43 also has mounted thereon a feeding dog 46 provided with a toothed upper surface in the usual manner. It will be seen that the cam 45 will impart tothe arm 43 and the feeding dog 46 an up and down movement while at the same time the cam 36, acting through the connections just described, imparts a'horizontal reciprocating movement to said dog. These movements are so coordinated b proper adjustments of the eccentrics that t e feeding movement is given to the Ydog 46. I The horizontal extent of such movement may be adjusted by adjusting the'block 39 along the arm 35.

i' The sleeve 42 also carries a rearwardly extending arm 47 having an extension 48 upon which is mounted a block 49 adapted to slide in a slot 50 in the side of the dog 32. Thus the arm 47 vand its extension 48 provide a support for the dog 32 which will impart to the latter an up and down movement correspond- Y ing to that of the arm 43. At the same time, the slot 50 permits a horizontal movement of the dog 32 relatively to the arm 43. As previously described, the extent of horizontal movement of the dog 32 may be adjusted by adjusting the block 28 along the arm 22. Accordingly, the horizontal movements of the dogs 46 and' 32 may be independently adj usted and may have different extents. The adjustment is ordinarily made so that the dog- 32 will have a greater horizontal movement than the dog 46. This is in order that when sewing knit goods, which is liable to stretch under theV pull usually applied by the operator, this dog 32 will tend to gather or pucker the material under the needles. The result in fact is that the extra movement ofthe dog 32isi1nply compensates for the stretch of the goods applied by the operator.

Trimming mechanism Vof an A'arm 55, the' other end of which is fixed to a rocl shaft 56. The shaft 56 is journaled at 57 vin a sleeve 58 supported in any suitable manner in the casting The sleeve 58 has threaded thereto a plug which provides another vbearing for the shaft 56. Within the sleeve 58 a coil spring 60 surroundsthe shaft 56, bearing at one end against a collar 61 secured yto the shaft and at the otherend against the plug 59. The shaft 56 has xed thereto at its end an arm 62, (see Fig. 3) which has adjustably mounted therein a trimmingcutter The operation of the shaft 11 causes theeccentric 51 to roclr the shaft 56 so as to impart a vertical reciprocating movement to the cutter 63. This cutter has a bevel cutting edge as shown in Figs. land 3 and bears against a corresponding stationary cutter 64.. Thev cutter 64 is supported on an arm 65 supported in any suitable manner on a pedestal 66 on the base 1. The'setrimming cutters are so located with respect to the otlvier/mechanism that the superfluousmaterial lis trimmed from the edge of the work just before the same passes to the stitching mechanism.

Plain, stitching` 'mec/amant The needle bar 17 carries two needles 67 and 68. These needles are mounted vertically mechanism adapted to sew a plain' seam rslightly displaced in a` lateral direction. Both `needles `are provided with *eyes '69 adapted to receiver a thread Vvin the usual manner.

Cooperating with theneedle" `67 ,which is located in advanceof the other needle, stitchl ing mechanism is provided adapted to sew a plain seam. This mechanism comprises a looper 70 mounted on and fixed to the shaft 31 running transversely of the base from frontA to rear just below the needles. This shaft has bearings in a sleeve 71 mounted `in the pedestal 66 and a sleeve 72 having a bearing in a block 7 3`mounted on .the `base 1. b The shaft 31 is loosely mountedv in these'sleeves so as to be ,capablev of both .rotary "and endwise movement therein. The sleeve 72 is also mounted for turning movement `in the block 73 but is confined against endwise movement by a pair of collars 74 iixed to the sleeve on opposite sides ofthe block 73. Secured to the sleeve 72 is a collar 75 havin an arm 76 which carries at-its end a pin 7 extending along theshaft31 and passing through a perforationin the looper as will be seen from Fig. 7.

The shaft carries, at an intermediate portion thereof, a spiral gear 78 adaptedv to mesh with a similar gear 79 on a transverse shaft 80, having bearings 81 on the base 1. (See F ig. 4.) The forward end of the shaft carries a crank disc 82 whichis connected by a link 83 to an arm.` 84 on the sleeve 75. It will be seen that rotation of the shaft y5 will cause rotation of the shaft `80 through the agency of the spiral gears 78 and 79 which in turn by means of the link ,-872 will rock the sleeve 72 so as to imparta corresponding movement to the looper 70.

The shaft 5 carries an eccentric 85 adapted to work in a fork 86 having an arm 87 attached to the shaft 31. This arm is lattached by means of a collar 88loosely fitting said shaft and confined by the collars 89 xed tol the shaft. The eccentric is thus effective in imparting an endwise movement tothe shaft 31 while at the samejtime permitting a rocking movement thereof to yprovide for rocking the looper 70.l f

The relation ofthe movement of the looper 70 to that of the needle 67 is such that the vlooper takes a loop from the needle after the 'i latter has pierced the work, holding the loop as the needle is retracted andthen shifting l endwise of the shaft 31 to a position in front `of the needle in a manner well known in the art formaking a chain stitch seam. The needle 67 and its cooperating parts including the looper 70 therefore, provide stitching which, in the present case, jis of the V.chain stitch type. A

' Over-stitch mechanism The needle 68 adapted'to cooperate-with f stitch-ing mechanism which will now be de` "scribed to 'forman over-stitch coveringthe edge of the work'. u y

The Vshaft 80 carriesl at its rearward `end a second crank disc 90 whose crank pin 91):

slidable and rotatable therein. It will be seen y 'that by these connections rotation oftheshaft `80 will impart a rocking` movement to the `shaft 97.

Mounted on the shaft 5 is an eccentric `99' workinginV a fork'100 which carries an arm 101 having lateralextensions 102 perforated to receive the shaft 97 on opposite sides of the arm 98 as shown in Fig. 6. The arm 98 being confined between the extensions 102 and said arm being fixed-to the shaft 97, it will be seen that reciprocation of the fork by the eccentric cam 99 will cause the shaft 97 to shift Vendwise in thesleeve 96. The shaft is thus givenboth a rocking movement by the link 92 and an endwise shift by the cam 99.

The sleeve 71 has fixed to the end'thereof avlo'oper 103. This looper is alsoperforated f' .and the pin 77 see'FigQ7) extends-`through `said perforation in a manner similar to that described for the looper 70. The movement of .the pin will therefore cause a rocking movement to'beimparted to the looper 103 `-aswell as to the looper 70. The looper 103 is, however, secured against endwiseshifting.

vWhile the looper 70 is positioned to cooperate with the needle .67, thelooper 103 is lcorrespondingly positioned to cooperate with'the `needle 68 but in a somewhat differentmanner as will presently be described.

Mounted on the end of the rockshaft :97 is a second looper 104. This looper hasimparted to it a rocking movement and an endwise shifting movement as just described for the shaft 97,. The needle 68, the looper 103 and the'looper 104 cooperatev to form the .overstitch seam as will now be described.

The movementsof the needle 68 andthe f .loopeis103 and 104 are so coordinated as to form an over-stitch seam as follows, referring particularlyto.Figures 9, 10, and 11. 4The needle 68descends, piercing the work represented at105. As the needle is retracted a loop `is formed in the needle thread 106. The looper 103 which itself carries a thread 107, now advances and enters the loop in the needle thread, taking such loop from the needle as The looper 103 retains this loop and advances to its furthermost pothe latter retracts.

sition. Upon retraction of this looper va loop is` formed in the thread 107 and the second `looper104 now risesand-enters this loop, takingthesamezfrom the iirstlooperlO-f-as i I ing the the latter retires. The looper 104 nowv rises,

retaining its loop in the thread 107. As the looper 104 rises, due to the rocking movement of the shaft 97 imparted bythe crank 90, it shifts forwardly at the same time in response to the action of the cam 99. The looper 104 now passes to the front of the needle 68 and passes over the edge of the work to a position adjacent the needle. This looper also carries a thread 108 which is carried upward therewith. The needle 68 now begins to descend for another stitch. In so doing it takes a loop in the thread 108 from the looper 104 which is then retracted. This sequence of operations is then repeated for successive stitches. It will be seen that the looper 103 carries its thread forwardly and the looper 104 after taking a loop from the first looper carries its thread up over the edge of the work to be caught in turn by the needle and stitched down on the upper side of the work. A succession of such stitches therefore forms a cover stitch extending over the edge of the work and binding the same against ra-veling and at the same time improving the-appearance thereof. l

As previously stated, the needle 67, formplain seam is spaced in advance of the needle 68 Aforming the over-stitch seam. At the same time theneedle 67 is displaced laterally with respect to the other needle in such va direction that the plain seam rformed by the first needle will be included and covered by the stitching formed by the second needle as will be seeny from Figures 12 and 13.

In the operation of this machine the work is placed in the usual manner upon the cover plate or table 109 which is placed over the mechanism described above as shown in Figure 1. This plate is suitably perforated to accommodate the needles, the feed dogs and the trimming cutters. A presser foot 110 mounted on a bar 111 and controlled by a spring 112 is provided in the usual manner. The work having been placed upon the table and the machine started, the work will be fed forward by the operation of the feeding dogs. Just before arriving under the needles the rough edgev of the work is trimmed off by the `cutters 63 and 64. The work then passes under the needles, the needle 67 and its cooperating mechanism sewing a plain seam along the trimmed edge and at a fixed distance therefrom. The needle 68 and its cooperating mechanism thereafter adds an overstitch seam which applies its stitching over the edge of the work and so as to include the plain seam. Thus the work is not only securely sewed together but the plain seam is also neatly bound by the cover stitch and these two functions are accomplished at a',

single operation of the machine.

It will be seen, therefore, that this invention provides a machine which is capable of sewing together such material as knit goods greater output `may be obtained therewith.

It will be noted that the movements of all thek loopers arey accomplished by mechanism which involves only uniplanar movements, ormovements whichdo not deviate from a single plane. Accordingly, the mechanism involves only pivotal connections and plain sliding movements. Such construction involves parts which are easily and simply manufactured with great accuracy, so that they may be'made interchangeable. Itis also clear that such movements provide for rigid support of the various parts so' that this machine may be driven at a high speed without changing the accuracy of movements of the co-operating parts. Accordingly, the loopers willY always co-operate accurately with the needlesand with each other, and there will be no danger of dropping stitches or similar' faults, even when operating at a high speed.

Itis obvious that various changes may be made in details ofconstruction without departing from the spirit of this invention. It is, therefore, to be understood that this invention is not to be limited to the specific details shown and described. y

' Having thus described the invention what is claimed is: y

, 1. In a sewing machine, stitching mechanism including, a pair of vertically moving needles, a looper shaft, a pair of loopers mounted to turn about said shaft, one of said loopers being secured against endwise movement, means for turning said loopers about said shaft to take a loop from each of said needles, and lmeans for shifting said shaft adapted to shift the other of said loopers transversely of its` loop-talringmovement.

2. In a sewing machine, stitching mechanism, comprising, a pair of vertically moving needles, a pair of loopers cci-operating therewith, connections adapted to move said loopers to tal-:ela loop from each of said needles, a third looper cooperating with one of said first Aloopers to over-stitch the work, and means independent of said connections adapted'to shift only oner of saidlirst loopers translversel of its loo J-talrinomovement.

3. In a sewing machine, stitching mechafnism, comprising, a pair of vertically moving ers to over-stitch the work, and means in'de- 2li rst loopers to over-stitch the work, means independent of said connections adapted to 'shift one of said first loopers transversely of shaft, and means for moving said shaft endwise. Y

In testimony whereof I afHX my signature this 11th-day of September, 1925.

HORACE F. GRUMAN.

and means independent of said connections adapted to shift only one of said rst loopers transversely of its loop-taking movement.

5. In a sewing machine, stitching mechanism, comprising, a pair of vertically moving needles, a pair of loopers co-operating therewith, connections having only uniplanar .movements adapted to move said loopers to take a loop from each of said needles, athird looper cooperating with oneof said first'looppendent of said connections adapted to slide one of said first loopers transversely of its loop-taking movement.

6. In a sewing machine, stitching mechanism, comprising, a pair of vertically moving needles, a pair of loopers cri-operating therewith, means for mounting said loopers for movement to take a loop from each ofsaid needles, means for moving said loopers together to-take a loop from each of said needles, a third looper cooperating `with one of said first loopers to over-stitch the'work, and means operating through said mounting means adapted-to shift only one of said first loopers transversely of its loop-taking movement. v i

7. In a sewing machine, looper mechanism, comprising, a bearing, a 4sleeve rotatably mounted therein, a shaft movable in said sleeve, a looper on said sleeve, and a looper Von said shaft. n

8. In a sewing machine, looper mechanism,

comprising, a bearing, a sleeve rotatably mounted therein, a shaft movable in said` sleeve, a looper on said sleeve, a looper on said shaft, and means for moving said shaft independently of said sleeve.

y 9. Inasewing machine, looper mechanism, comprising, a bearing, a sleeve rotatably mounted therein, a shaft movable in said sleeve, a looper on said'sleeve, a looper on said shaft, means for turning said loopers about said shaft, and means for ino-ving said shaft endwise.

10. In a sewing machine, looper mechanism, comprising, a bearing, a sleeve rotatably monnted therein, a shaft movable in said sleeve, a looper on said sleeve, a looper on said shaft, an element engaging said loopers `and movable to turn said loopers about said iis 

